Geolocation prepopulating user's country in checkout?

Does anyone know of a way that we can prepopulate the user's country, and in effect their region, in the checkout form? As it strands right now everything defaults on UK, but is a person visits from the US, then ideally the country should be USA and the region dropdown changed to US states automatically.

Anyone? Thanks in advance for your help!

Anyone?

This mod pretty much does what we're looking for, more than since we're only looking to have to country and region prepopulated, but unfortunately it doesn't look like it's getting much support...

http://www.opencart.com/index.php?route ... ESC&page=5

The response to my questions is overwhelming.

It looks like that extension has vanished now so I guess it's no longer supported.